Book recommendations about Infinity for an 11 yo?

My 11yo has been intrigued for years by the concept of infinity. She says she thinks about it all the time. Her latest question was, "Is 1/∞ equal to zero?" Then, "If it's equal to zero and you multiply it by ∞ would you get 1 or 0?" I think the questions she comes up with are interesting, but I don't know how much help I am to her in thinking through them.

So I'm looking for some book recommendations for her - something that wouldn't be too far above her cognitive reach. She is currently doing Beast Academy 5C, so that's where she's at mathematically. She catches onto math concepts quickly. She'd be able to handle some basic algebra and geometry, but not much past that yet. She's very visual-spatial, so would be able to understand books with visual explanations easily. She can read well, though she doesn't usually read books above middle school/early high school level.

No recommendation, but years ago my dad took a university class in infinite math... questions like "what is infinity-infinity? Or infinity+infinity" (and no, I don't remember the answers...). So she is thinking of university level questions!